The construction aspect of the project will take about two and a half years, concluding on Jan. 27, 2021.

Amec will continue to monitor the site for about 700 days, predicting to fully close out the project on Oct. 11, 2023.

Carlsbad Brine Well Authority designee John Heaton addresses the Radioactive and Hazardous Waste Legislative Committee Friday in Carlsbad. Heaton assured the committee that an emergency management plan was in place to respond to a collapse of the brine well.(Photo: Courtesy Photo)

How will well be plugged?

The cavity beneath the former well site is not a completely open void, read Amec’s proposal, which was accepted in response to a request for proposal (RFP) by the Carlsbad Brine Well Remediation Authority, and arm of the New Mexico Energy, Minerals and Natural Resources Department (EMNRD).

Based on geological testing, there was believed to be a network of solids and brine solution left behind from the well’s injection.

To restore the ground’s stability, 24-inch boreholes will be drilled around the property, starting in its northern corner, and proceeding south before ending in the center of the cavity.

Then in the second phase, a system of columns made with the low-mobility grout will be created to provide stability to the lower portions of the cavern.

The existing brine solution and residuals will be densified for additional integrity, read the proposal.

Reusing the materials already underground, read the proposal, can reduce the amount of grout needed and cut down on waste.

CLOSE

The area affected by the potential sinkhole encompasses about 3.27 acres near 3005 S. Canal St. The well itself is about 300 feet wide and 700 feet long. The depth of the cavern is estimated about 600 feet below the surface.
Wochit

“This remedy both minimizes the total volume of grout needed for roof support and minimizes the volume of waste material that needs to be removed from the cavity,” read the proposal.

Any brine or residuals not used in the project will be transported off-site and properly disposed of.

The project will see about 833,000 cubic feet of grout pumped into the cavity, and about 74,000 barrels of brine removed.

While some subsidence is expected, Amec believes its method of filling the cavity will prevent any danger to surrounding properties or the environment.

“The selected method of remediation will protect public welfare, the environment, and property,” read the proposal. “Our remedy will have long-term effectiveness and permanence, and will eliminate the potential for an uncontrolled collapse of the cavity roof and the development of a catastrophic sinkhole at the surface.”

A map of the South Y highway junction on the south side of Carlsbad where a brine well could soon collapse, creating a massive sinkhole.(Photo: Google Maps)

Two business to relocate

But before Amec can begin its work, EMNRD Cabinet Secretary Ken McQueen, who chairs the Authority, said two nearby properties are a concern.

The Circle S Feed Store at 2907 S. Canal St., and the Kingdom Hall of Jehova’s Witness both fall within the collapse zone, and in the property outlined by Amec’s proposal as needed for the project.

“Frankly, I think it’s EMNRD and the OCD (Oil Conservation Division, a subsidiary of EMNRD) that created this problem with their lack of oversight,” Heaton said. “Everybody feels badly about it. We’re all very concerned. It takes time for them to move or find another avenue for their businesses.”

Wally Menuey, owner of the feed store said he expected negotiations to begin in earnest by June.

He declined to comment further on his plans until reaching an agreement with the State.

"It's going to impact my business big time," Menuey said.

The church did not respond to a request for comment.

The Authority will next meet July 11.

Adrian Hedden can be reached at 575-628-5516, achedden@currentargus.com or @AdrianHedden on Twitter.